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ON MEASURES

confounded two perfectly distinct ideas, namely,
 measuring the value of commodities, and
ascertaining in which commodity, and in what
degree, the causes of value have varied.
For suppose we had such a commodity as he
requires for a standard : suppose, for instance,
all commodities to be produced by labour
alone, and silver to be produced by an invariable
 quantity of labour. In this case silver
would be, according to Mr. Ricardo, a perfect
measure of value.” But in what sense? What
is the function performed? Silver, even if invariable
 in its producing labour, will tell us
nothing of the value of other commodities.
Their relations in value to silver, or their prices,
must be ascertained in the usual way, and
when ascertained, we shall certainly know the
values of commodities in relation to each other :
but in all this there is no assistance derived
from the circumstance of the producing labour
of silver being a constant quantity.
But it is the fluctuations of commodities
which this invariable standard is to ascertain or